Magnetically controlled electron multiplier switch

ABSTRACT

In the apparatus disclosed, a block forms a plurality of channels between input and output apertures. The inside surface of each channel is covered with secondary emissive material. Suitable mechanical, electromagnetic, or electrostatic switches direct the electron flow from one channel to another at junctures within the block.

United States Patent Nagao et al.

Aug. 5, 1975 MAGNETICALLY CONTROLLED ELECTRON MULTIPLIER SWITCH Inventors: Kazuyoshi Nagao, Yokohama;

Koichi Morikawa, Tokyo, both of Japan Assignee: Canon Kabushiki Kaisha, Japan Filed: Mar. 26, 1973 Appl. No.: 345,249

Related US. Application Data Continuation of Ser. No. 67,130, Aug. 26, 1970, abandoned.

Foreign Application Priority Data Sept. 29. 1969 Japan 44-77657 US. Cl. 313/103; 313/95; 328/244 Int. Cl HOlj 43/14; HOlj 43/22 Field of Search 328/243; 313/103, 104,

[56] References Cited UNITED STATES PATENTS 2,806,141 9/1957 Adams 328/242 X 2,807,741 9/1957 Fulmer... 313/105 2,841,741 7/1958 Wiley 315/12 2,945,144 7/1960 Schmidt et a1 313/104 X 3,184,633 5/1965 White et al. 315/12 Primary ExaminerRobert Segal Attorney, Agent, or FirmT0ren and McGeady 1 Claim, 17 Drawing Figures [(1/1 I II 1 11 r/ I II I l I I I I If I IIr Q o o o II II 1 I1 I II I 111/ I I r \LL} II I! 1 I I I I I LLL I I II Ill 77 v l7ZD PATENTEDAUB5I975 3,898,499

SHEET 1 Ultra violet Rays Hill! Heat Treatment Hydrofluoric Acid Treatment Lid Inner Surface Treatment INVENTORS KAZUYOSHI NAGAO KO C H I MORI KAWA WCW 0/770 Tmm r ATTOR N EYS PATENTED AUG SL975 3, 8-9 8 .499

Our". 0 Cal-L L.

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Attachment of Sectors Inner Surface Treatment INVENTORS I KAZUVOSHI NAGAO KOICHI MORI KAWA Bye/77c 40 we 8mm ATTORN EIS PATENTEUAUB 5M5 3,898,499

SHEET 3 FIG.3

KAZUYOSHI NAeAo KOICHI MORIKAWA W7: amd 1m WTORNEYS PATENTEDAUB 5|975 3,898,499

KAZUYOSH/ NAeAo .ny ROICH MOR'RAWA E ATTO R N EYS SHEET PATENTEU AUG 5M5 WCWd/fld T ATTORNE g PATENTED Mm 19 5 SHEET FIG.8

I N VEN TORS MM m5 6A Ta M I N. 1 MR 0 SM W MM 6 KK W PATENTED AUG 51975 SHEEF INVENTORS KAZUYOSHI NAGAO by KOICHI MORI KAWA 0 7a WWW 7m ATTORNEYS PATENTED AU[; 5 \975 SHEET 1 0 FIG.14

, INVENTORS KAZUYOSHI NAGAO y KOICHI NORI HAWA PATENTED we 51915 INVENTORS KA'ZUVOSH! NAGAQ BY Kmcm MORll-(AWR wcyaw woven/1% ATTORNEVS I MAGNETICALLY CONTROLLED ELECTRON MULTIPLIE'R SWITCH This is a continuation of application Ser. No. 67.130 filed Aug. 26. 1970, now abandoned.

The present invention relates to the so-called channel type photo multiplier.

I-Iitherto known tubular pho'tom-ultipliers belong to such types as micro-channel plates. These are obtained by means of a process similar to the one for manufacturing of fiber optics. Some of these photomultipliers are provided with a layer of poor conductivity on the tubular inner surface thereof orexhibit a low conductivity by virtue of the tubular body itself. The electrically conductive layer or the tubular body itself is coated with secondary-electron emission material. The electrically conductive surface or electrically conductive tubular body and anode are subject to a voltage and both ends thereof are subject to avacuum in order to obtain multiplication.

The present invention is to p r'ovide amethod for obtaining a tubular photo multiplier which is cheap and easy to reproduce, as well as to afford means of variable sensitivity or available isolation and polarization (branching). v y,

The present inventionwill now be explained with reference to the accompanying drawings on the point in question such as method for making tubular body, method for isolation, branching and coupling, and variation of sensitivity in sequence The present invention shall be described in detail referring to the attached drawings in which:

FIG. 1 is a diagrammatic explanatory sketch showing the processing of photoform method relating to the present invention, I

FIG. 2 is a diagrammatic explanatorry sketch showing the processing of sector method relating to the present invention, 7

FIG. 3 is a diagrammatic explanatory sketch showing the working stages of press method relating to the present invention, v I

FIG. 4 is a diagrammatic explanatory sketch showing an assorted method obtained by combination of;the foregoing methods shown in FIGS. 1 3,

FIG. 5 containing the drawings designated by symbols (a) and (b) are diagrammatic explanatory sketches respectively showing switch mechanism provided in an example in the form of an embodiment relating to the present invention,

FIG. 6 and FIG. 7 containing thedrawings designated by symbols (a) and (b) are diagrammatic explanatory sketches respectively showing switch mechanism provided in the other embodiment-according to the present invention,

FIG. 8 containing the drawings indicated by symbols (a), (b) and (c) are diagrammatic explanatory sketches respectively showing an embodiment for the processing of switching an electron current, i I

FIG. 9 containing the drawings indicated by symbols (a) and (b), FIG. 10 containing the drawings indicated by symbols (a), (b), (c) and (d). and'FlG. 11 containing the drawings designated by symbols (a) and (b) are diagrammatic explanatory sketches respectively showing the other embodiment for'the processing of the switching mechanism,

FIG. 12 is a diagrammatic explanatory sketch showing an embodiment for the mechanism to vary the ratio of multiplication,

FIG. 13, FIG. 14 containing the drawings designated by symbols (a) and (b), FIGS. 15 and 16 are diagrammatic explanatory sketches respectively showing another embodiment, particularly in FIGS. 16 and 17 are diagrammatic explanatory sketches showing an embodiment respectively for tubular type photo multiplier.

As shown in FIG. 1, the photoform method may be used for manufacturing a tubular photomultiplier. In the photoform method, glass containing silver and cerium oxide is subjected to radiation with ultraviolet rays and treated with heat. The treated glass is crystallized at the particular portions subjected to radiation. These portions are then more easily leached out by hydrofluoric acid than the other part of said treated glass where it is not crystallized.

to take advantage of the foregoing feature the tubular body (1) is covered with the mask (2) as shown in FIG. 1. The tubular body (1) is treated with heat after being irradiated with ultra-violet rays. It is then easily etched chemically to form a slot or groove of simple or complicated shape and is covered with a lid (3). In FIG. 1 at the top, several vertical arrows indicate an emission of ultra-violet rays. Single arrows in vertical alignment at the interspace between the top and the intermediary portion represent the subsequent heat-treatment and treatment with hydrofluoric acid. The arrow disposed above the lower portion indicates a lid for covering finished grooves, and an arrow disposed below said lower portion represents the next processing step including treatment of the inner surface.

FIG. 2 illustrates a method for manufacturing a tubular photo multiplier by means of the sector method. I-lere each glass block (4) is piled up one above the other and they are adhered to each other as well as to a piece of glass plate (5). The stacked glass blocks are covered with a lid (6) to form a hollow body. The inner surface of the body is coated with secondary electron.

The third example shown in FIG. 3 is a press working method. Here the base material (7) is pressed and a lid (8) is fixed to said pressed material (7), the inner surface of which is coated with secondary electron emission material. However, the inner surface is not smooth after press treatment only and has to be polished as the occasion demands and the mechanical or chemical polishing steps is properly carried out as well.

FIG. 4 shows another method for making use of the manufacturing methods shown in FIGS. 1, 2 and 3 respectively, wherein bodies designated by reference numerals 9 and 10 are formed in respective shapes as shown in this drawing and are combined with each other after being coated respectively with secondary electron emission material. They are thereby effective to make a tubular photo multiplier comparatively easily.

After the tubular photo multiplier has been manufactured according the method hereinbefore described, either an electric conductive layer is provided thereon or the base material being used is an electric conductive glass. Thus the secondary electron emission material is deposited on the surface of said layer or on the inner surface of said tubular body. A tubular photo multiplier made by to the foregoing method is available for the process of branching, coupling, isolation and variation of multiplication by means of method hereinafter described. An embodiment according to said method is shown in FIG. 5.

FIG. 5 shows a switch mechanism wherein a block element (1 1) shown in the drawing designated by symbol (a) in to FIG. 5 is adapted to be displaceable to the right and left against a block element (12). Thus an electron coming from one of the block elements (13), (13) or coming from both of said block elements (l3), (13) does not pass through to a block element (15) due to the position of a block element (14).

In this instance, an electric conductive surface is adapted to be coupled through a switching part.

Another type of switch mechanism is available shown in FIG. 6 which is a modification of an example shown in FIG. 5 wherein glass plate designated by reference numeral (16) in this drawing is provided with an aperture (l7) pierced therethrough and said glass plate (16) or (18) is adapted to be movable to the right and left for changing the electron flow. or channel FIG. 7 containing the drawing designated by symbols (a) and (b) show another embodiment of switch mechanism respectively wherein an electron path designated by reference numeral (19) is conducted to the other path designated by reference numeral (20) while an electron path, designated by (21) is directed to the other path (22).

Accordingly the foregoing switch mechanism is actuated so that when an electron current flow from (19) to (20),(2l) and (22) are isolated from each other and when, to the contrary, (21) and (22) conduct to each other, (19) and (20) are isolated from each other. An encircled portion designated by reference numeral (23) disposed at the center of FIG. 7 is a movable member for switching an electron flow and is adapted to be rotatable on the constituent element (24).

FIG. 8 illustrates an embodiment of a switch mechanism for switching an electron flow directly by mechanically switching the film of secondary electron emission material. In the drawing designated by the symbol(b) of FIG. 8, an electron passage (25) is adapted to intersect the film (26) in case said electron currency (25) being emitted. When the secondary electron emission material is coated on the surface of said film (26), an electron flow will be switched without causing any loss of said electron current. Moreover, the opening and closing operation of the film is arranged to be synchronized with the electric charge on an anode. Thus it can be expected to be obtainable more favourable results.

FIG. 9 shows an another embodiment of a switch mechanism. This one utilizing the effect of a magnetic field on a moving electron. An electron current emitted in the direction indicated by an arrow (27) is oriented toward the direction designated by numeral (29) in an magnetic field 28 generated by an electromagnet and the like as shown in the drawing designated by symbol (a) of FIG. 9. The magnetic field is passes through from the front surface to the rear surface in the direction perpendicular to the plane of said drawing. When an electron current is to flow toward the direction (30), the magnetic field extends in the opposite direction.

With the scope of the magnetic field appropriately selected, an electron current can pass close to the wall at one side. In this way, the switch mechanism can op erate efficiently. Speedy switching is achieved by reorienting the magnetic field synchronously with the operation of the switching anode.

FIG. 10 shows further embodiment of switch mechanism, by way of an example, actuated by static electricity in order to achieve the aim thereof wherein this mechanism is arranged some kind of mechanism similar to a grid of a vacuum-tube at the branching point according to the principle that electric charge of the same kind will be repulsed against each other while electric charge of a different kinds will be attracted to each other.

For instance, the positive or negative, or zero electric voltage will be charged on the grid wiring which is prearranged.

When an electron currency is adapted to pass in the direction from the right to the left, that is, from (31) to (32), the grid (33) is charged zero or weal positive voltage while the grid (34) is charged negative voltate so as an electron. will be repulsed against each other as shown in FIG. 10. In such a case as mentioned above, each of said grids will not be charged equivalent voltage in such a manner that the grids disposed at the center portion will be charged higher than those in the rest of other portions and the outer portion being disposed the grids, the lower voltage being charged thereto, or it can be obtained efficiency with the result of branching operation by means of different positional arrangement as shown in the drawings wherein said grids are arrayed slantwise in downward direction, however, as occasion arises, they are apt to be arrayed in a row forming a concaved shape or to be arrayed linear. Also an electric conductive layer is subjected to be divided to each other as shown in the drawings designated by symbols (b), (d) and (d) respectively of FIG. 10, and in case, an electron currency, for example, being desired to pass towards the channel of an element (35), the other elements (36) and (37) are connected to an element (35) so as another element (38) is not loaded with electric voltage.

In FIG. 10, the reference numeral (39) designates an anode, (40) indicates secondary electron emission surface, (41) represents an electric conductive surface, (42) is a cylindrical body respectively, such constitutional mechanism as mentioned above will be able to carry out branching operation for an electron currency without any loss thereof.

FIG. 11 shows a switch mechanism similar to the one shown in FIG.- 10 wherein an electron currency is adapted to be passed in any optional direction of orientation as desired by means of mechanically moving the plate (43) which is loaded with electric charge.

Now the operation of mechanism for producing variation of multiplication ratio will be described hereinafter: I

FIG. 12 showsa mechanism telescopically constituted to achieve an aim for variation of multiplication ratio by changing the length of a cylindrical body to be extended as well as to be retracted in order to vary multiplication ratio.

In FIG. 12, the reference numeral (44) is an interior tube of the cylindrical body and an electron currency is adapted to pass therefrom. (45) is an exteriorltube of said cylindrical body, (46) represents a layer of secondary electron emission material, (47) is an electric conductive surface, (48) designates a conductive material connecting between each of electric conductive surfaces of said interior tube (44) and said exterior tube (45).

FIG. 13 shows a mechanism as an example in the form of another embodiment, similar to the one set forth in the foregoing case, for obtaining variation of multiplication ratio carried out by means of extracting an anode as well as retracting the same whereby said multiplication ratio will be decreased in case said anode being retracted further inner part of the cylindrical body while said multiplication ratio will be increased in case said anode being positioned close near to the opening within the cylindrical body, such that said ratio is to correspond to the extent of distance from the opening to the position of said anode within the cylindrical body.

In FIG. 13, the reference numeral (49) designates a cylindrical body, (50) is an electric conductive surface, (51) indicates the surface of secondary electron emission material, (52) is an anode to be reciprocally displaceable in the forward and backward directions, (5 3) is a conductive material and (54) is an insulator.

FIG. 14 is an explanatory sketch showing still further embodiment of device for sequential variation of multiplication ratio similar to those shown in FIGS. 12 and 13 wherein the reference numeral (55) designates the cylindrical body, (56) indicates an electric conductive surface, (57) is secondary electron emission surface and (58) indicates a pivotal covering plate, and the greater magnitude being the inclination angle 0 formed by pivotal movement of covering plate, the lesser an electron currency being passed. It is not sufficient to be effective for causing variation of multiplication ratio, negative or positive voltage is subjected to be charged in addition, so that said covering. plate (58) is sequentially charged with electric voltage ranging from positive to negative.

Accordingly it can be obtained optional variation of multiplication ratio due to angular magnitude of inclination of the covering plate (58) and power of voltage to be charged thereto as positive or negative voltage.

In FIG. shows another further embodiment for varying multiplication ratio constituting rectangular elements (59) and (60) grouped together as shown in the drawing, both of which elements are made, for instance, of glass and the like wherein multiplication ratio is adapted to be varied by sliding said elements with each other to lateral directions with the result of changing ration in length and width. In the drawing, the reference numeral (61) designates secondary electron emission material and an electric conductive layer.

In FIGS. 16 and 17, tubular photo-multiplier is shown respectively in a form of an embodiment.

FIG. 16 shows an read-out head for punch cards and the like comprising a number of tubes, each of which, as shown in the drawings, is arranged to dispose at the position facing to corresponding aperture provided on the punch card (62) in order to read the light passing through each of said apertures by means of multiplication of tubular photo-multiplier (63).

In FIG. 16, the reference numeral (64) represents each of channels and (65) is an anode.

In FIG. 17, a central member (66) is subjected to be rotated mechanically for scanning the light emitted to the channel (67). In the drawing, an anode is fixed at the point designated by the reference numeral (68).

What is claimed: I

l. A multiplier apparatus, comprising a member forming an elongated passage, the inside of said member being coated with secondary electron emission material, means for generating an electron flow in the longitudinal direction of the passage, magnetic field generating means provided outside the member for generating a magnetic field transverse to the longitudinal direction of the passage and a shielding plate inside the member and remote from the opening thereof, said shielding plate having its surfaces coated with secondary emission material and dividing the two sides of the passage longitudinally from each other and being oriented parallel to the magnetic field, said apparatus including means for varying the magnetic field to control the flow of the electrons to one side or the other. 

1. A multiplier apparatus, comprising a member forming an elongated passage, the inside of said member being coated with secondary electron emission material, means for generating an electron flow in the longitudinal direction of the passage, magnetic field generating means provided outside the member for generating a magnetic field transverse to the longitudinal direction of the passage and a shielding plate inside the member and remote from the opening thereof, said shielding plate having its surfaces coated with secondary emission material and dividing the two sides of the passage longitudinally from each other and being oriented parallel to the magnetic field, said apparatus including means for varying the magnetic field to control the flow of the electrons to one side or the other. 